JP2541030B2 - Novel crystal of hydroxyindium phthalocyanine and electrophotographic photoreceptor using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel crystal of hydroxyindium phthalocyanine useful as a photoconductive material and an electrophotographic photoreceptor using the same.

[0002]

2. Description of the Related Art Phthalocyanine is used for paints, printing inks,
It is a useful material as a catalyst or an electronic material, and in particular, has recently been extensively studied as a material for an electrophotographic photosensitive member, a material for optical recording, and a photoelectric conversion material. Regarding electrophotographic photoreceptors, in recent years, the photosensitive wavelength range of organic photoconductive materials conventionally proposed has been changed to the wavelength of near infrared semiconductor lasers (780 to 780).
830 nm), and there is an increasing demand for use as a photoconductor for digital recording such as a laser printer. From this viewpoint, squarylium compounds (JP-A-49-105536 and JP-A-58-21416) , Triphenylamine trisazo compounds (JP-A-61-151659) and phthalocyanine compounds (JP-A-48-34189 and 57-148745).
Has been proposed as a photoconductive material for a semiconductor laser.

When an organic photoconductive material is used as a photosensitive material for a semiconductor laser, first, the photosensitive wavelength range is extended to a long wavelength, and then the sensitivity and durability of the formed photoreceptor are good. Things are required. The above-mentioned organic photoconductive material does not sufficiently satisfy these conditions. In order to overcome these drawbacks, the relationship between the crystal type and the electrophotographic characteristics of the above organic photoconductive material has been studied, and many reports have been made on phthalocyanine compounds.

[0004] In general, phthalocyanine compounds exhibit several crystal forms depending on the production method and treatment method, and it is known that the difference in crystal form greatly affects the photoelectric conversion characteristics of the phthalocyanine compound. . Regarding the crystal form of the phthalocyanine compound, for example, looking at copper phthalocyanine, in addition to the stable β form, α, π,
Crystal forms such as χ, ρ, γ, and δ are known, and it is known that these crystal forms can be mutually transformed by mechanical strain, sulfuric acid treatment, organic solvent treatment, heat treatment, and the like. (For example, U.S. Pat. Nos. 2,770,629 and 3,300).
Nos. 160,635, 3,708,292 and 3,357,989). In addition, JP-A-50-3
Japanese Patent No. 8543 describes a difference in crystal type of copper phthalocyanine and electrophotographic characteristics.

[0005]

However, the phthalocyanine compounds proposed in the prior art as described above are not yet satisfactory in terms of light sensitivity and durability when used as a photosensitive material. The development of phthalocyanine compounds that can be used as materials has been desired.

The present invention has been made in view of the above-mentioned situation in the prior art. That is, an object of the present invention is to provide a novel crystal of hydroxyindium phthalocyanine. Another object of the present invention is to provide an electrophotographic photoreceptor provided with a photosensitive layer containing hydroxyindium phthalocyanine.

[0007]

As a result of investigation, the present inventors have conducted a simple treatment on hydroxyindium phthalocyanine obtained by synthesis to obtain a novel crystal having high sensitivity and durability as a photoconductive material. Have been obtained, and the present invention has been completed.

That is, the hydroxyindium phthalocyanine crystal of the present invention has a Bragg angle (2θ ± 0.2 °) of 6.9 °, 9.8 °, and 14.9 in the X-ray diffraction pattern.
°, 16.3 °, 19.8 °, 25.4 °, 26.6 °
And having a strong diffraction peak at 28.1 °. Further, the electrophotographic photoreceptor of the present invention is characterized in that a photosensitive layer containing the above-mentioned hydroxyindium phthalocyanine crystal is provided on a conductive support.

The present invention will be described in detail below. The hydroxyindium phthalocyanine crystal of the present invention has a novel crystal form. 3 and 4 are X-ray diffraction patterns of those hydroxyindium phthalocyanine crystals.

These novel hydroxyindium phthalocyanine crystals can be manufactured as follows. First, for example, chlorindium phthalocyanine is hydrolyzed or acid-pasted in an acid or alkaline solution to synthesize hydroxyindium phthalocyanine, and the obtained synthetic hydroxyindium phthalocyanine is subjected to a solvent treatment or obtained by synthesis. After the obtained hydroxyindium phthalocyanine is subjected to amorphization and pulverization treatment, a solvent treatment is carried out, or the hydroxyindium phthalocyanine obtained by synthesis is subjected to wet pulverization treatment with a solvent using a ball mill or the like, and is produced by crystal transformation. be able to.

The solvent used in the above crystal transformation is
An aromatic solvent (toluene, chlorobenzene, etc.), a mixed system of several kinds, a mixed system of water and these organic solvents, etc., and 1 to 200, preferably 1 to 1 phthalocyanine.
0 to 100 is used.

Next, an electrophotographic photosensitive member using the above hydroxyindium phthalocyanine crystal as a photoconductive material in a photosensitive layer will be described. In the electrophotographic photosensitive member of the present invention, the photosensitive layer may be composed of a single layer or may have a laminated structure composed of a charge generation layer and a charge transport layer. When the electrophotographic photoreceptor of the present invention has a laminated structure, the charge generation layer is
It is composed of the hydroxyindium phthalocyanine crystal and a binder resin.

The binder resin may be selected from a wide range of insulating resins, and may be poly-N-vinyl carbazole,
It can also be selected from organic photoconductive polymers such as polyvinyl anthracene, polyvinyl pyrene. Preferred binder resins include polyvinyl butyral, polyarylate (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, acrylic resin, polyacrylamide. Insulating resins such as polyamide, polyvinyl pyridine, cellulosic resin, urethane resin, epoxy resin, casein, polyvinyl alcohol, and polyvinylpyrrolidone can be used.

The charge generation layer is formed by dispersing the hydroxyindium phthalocyanine crystal in a solution prepared by dissolving the binder resin in an organic solvent to prepare a coating solution and applying the coating solution on a conductive support. can do. In that case, the mixing ratio (weight) of the hydroxyindium phthalocyanine crystal and the binder resin used is 40: 1.
１ ： 1: 10, preferably 10: 1 to 1: 4. If the ratio of hydroxyindium phthalocyanine crystals is too high, the stability of the coating solution will decrease, and if it is too low, the sensitivity will decrease. Therefore, it is preferable to set the ratio in the above range. The solvent used is preferably selected from those that do not dissolve the lower layer. As a specific organic solvent,
Alcohols such as methanol, ethanol and isopropanol; ketones such as acetone, methyl ethyl ketone and cyclohexanone; N, N-dimethylformamide;
Amides such as N, N-dimethylacetamide, dimethylsulfoxides, ethers such as tetrahydrofuran, dioxane, ethylene glycol monomethyl ether;
Use esters such as methyl acetate and ethyl acetate; aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, and trichloroethylene; and aromatic hydrocarbons such as benzene, toluene, and dichlorobenzene. be able to.

The coating solution can be applied by a coating method such as a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a wire bar coating method, a blade coating method, a roller coating method, and a curtain coating method. . In addition, drying is preferably performed by drying by touching at room temperature and then drying by heating. The heat-drying can be performed at a temperature of 30 to 200 ° C. for 5 minutes to 2 hours in a static state or under blowing air. The thickness of the charge generation layer is usually 0.05
５5 μm.

The charge transport layer is composed of a charge transport material and a binder resin. Examples of the charge transporting material include polycyclic aromatic compounds such as anthracene, pyrene and phenanthrene, compounds having a nitrogen-containing heterocycle such as indole, carbazole and imidazole, pyrazoline compounds, hydrazone compounds, triphenylmethane compounds and triphenylamine compounds. And any known compounds such as an enamine compound and a stilbene compound can be used. Furthermore, poly-N-vinylcarbazole, halogenated poly-N-vinylcarbazole, polyvinylanthracene, poly-N-vinylphenylanthracene, polyvinylpyrene, polyvinylacridine, polyvinylacenaphthylene, polyglycidylcarbazole, pyreneformaldehyde resin, Photoconductive polymers such as ethylcarbazole formaldehyde resins are mentioned, which may themselves form the layer. In addition, as the binder resin, the same insulating resin as that used for the charge generation layer described above can be used.

The charge transport layer can be formed by preparing a coating solution using the charge transport material, the binder resin, and the same organic solvent that does not dissolve the lower layer as described above, and then applying the same in the same manner. Mixing ratio of charge transport material and binder resin (parts by weight)
Is usually set in the range of 5: 1 to 1: 5. The thickness of the charge transport layer is usually set to about 5 to 50 μm.

When the electrophotographic photoreceptor has a single-layer structure, the photosensitive layer comprises a photoconductive layer having a structure in which the hydroxyindium phthalocyanine crystal is dispersed in a layer comprising a charge transport material and a binder resin. . In that case, the compounding ratio (weight) of the charge transport material and the binder resin is
1:20 to 5: 1, the mixing ratio (weight) of the hydroxyindium phthalocyanine crystal to the charge transport material is 1:10
It is preferable to set to about 10: 1. As the charge transport material and the binder resin, those similar to the above are used, and the photoconductive layer is formed in the same manner as above.

As the conductive support, any material can be used as long as it is known to be used as an electrophotographic photoreceptor. In the present invention, an undercoat layer may be provided on the conductive support. The undercoat layer is effective in preventing unnecessary injection of charges from the conductive support, and has the function of enhancing the chargeability of the photosensitive layer. Further, it also has the function of enhancing the adhesion between the photosensitive layer and the conductive support. As a material constituting the undercoat layer, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl pyridine,
Cellulose ethers, cellulose esters, polyamide, polyurethane, casein, gelatin, polyglutamic acid, starch, starch acetate, amino starch, polyacrylic acid, polyacrylamide, zirconium chelate compound, zirconium alkoxide compound, organic zirconium compound, organic titanyl compound, And silane coupling agents. The thickness of the undercoat layer is 0.05 to
It is preferably set to about 2 μm.

[0020]

EXAMPLES The present invention will be described below with reference to examples. In Examples and Comparative Examples, unless otherwise specified.
"Parts" means parts by weight. (Synthesis example of hydroxyindium phthalocyanine crystal and its amorphous substance) 1, 3
-Diiminoisoindoline 30 parts, indium trichloride 1
1.4 parts of quinoline was added to 230 parts of quinoline and reacted at 200 ° C. for 3 hours, then the product was filtered, washed with acetone and methanol, and dried to obtain 29 parts of chloroindium phthalocyanine crystal. 3 parts of the obtained chloroindium phthalocyanine crystal was added with 1.5 parts of sodium hydroxide,
Add 30 parts of pyridine 18 parts, distilled water 70 parts,
Heat to reflux for hours. The crystals were filtered, washed with distilled water and dried to obtain 1.8 parts of hydroxyindium phthalocyanine crystals. The powder X-ray diffraction pattern is shown in FIG. The crystals were pulverized in an automatic mortar for 6 hours to obtain amorphous hydroxyindium phthalocyanine. The powder X-ray diffraction pattern is shown in FIG.

Example 1 2.0 parts of the amorphous hydroxyindium phthalocyanine crystal obtained in the synthesis example was mixed with 60 parts of water and 6 parts of monochlorobenzene.
Part of the mixed solvent and 120 parts of 1 mmφ glass beads were stirred in a ball mill for 24 hours, and the crystals were washed with methanol and dried to obtain 1.5 parts of hydroxyindium phthalocyanine crystals. FIG. 3 shows a powder X-ray diffraction pattern of the crystals.

Example 2 2.0 parts of amorphous hydroxyindium phthalocyanine crystal obtained in the synthesis example and 60 parts of chlorobenzene, 1 mmφ
1. Stir in a ball mill for 24 hours with 120 parts of glass beads, wash the crystals with methanol, and dry.
5 parts of hydroxyindium phthalocyanine crystal was obtained. The powder X-ray diffraction pattern of this crystal is shown in FIG. 4, the infrared absorption spectrum is shown in FIG. 6, and the visible light / near infrared absorption spectrum is shown in FIG.

Example 3 Hydroxyindium phthalocyanine 1 obtained in Example 1
Part is polyvinyl butyral (trade name: S-REC BM
-S, 1 part of Sekisui Chemical Co., Ltd.) and cyclohexanone 1
0 parts with a glass bead and treated with a paint shaker for 1 hour to disperse. Then, the obtained coating solution was applied on an aluminum substrate by a dip coating method,
The resultant was dried by heating at 0 ° C. for 5 minutes to form a charge generation layer having a thickness of 0.2 μm.

Next, the following structural formula

Embedded image 1 part of a compound represented by

The following structural formula

Embedded image 1 part of poly (4,4-cyclohexylidenediphenylene carbonate) is dissolved in 8 parts of monochlorobenzene, and the obtained coating solution is applied to an aluminum substrate on which a charge generation layer is formed by dip coating. Apply, 1
By heating and drying at 20 ° C. for 1 hour to form a charge transport layer having a thickness of 20 μm, an electrophotographic photosensitive member was produced.

Example 4 An electrophotographic photosensitive member was produced in the same manner as in Example 3 except that the hydroxyindium phthalocyanine used in Example 3 was replaced with the hydroxyindium phthalocyanine obtained in Example 2.

The obtained electrophotographic photosensitive member was subjected to normal temperature and normal humidity (2
0 ° C, 40% RH), low temperature and low humidity (10 ° C, 15% RH)
Electrostatic copy paper tester (EPA-8100, Kawaguchi Electric Co., Ltd.) under high temperature and high humidity (28 ° C, 80% RH) environment
The following electrophotographic characteristics were measured using V _DDP : Surface potential 1 second after negative charging by performing a corona discharge of -6.0 KV. E _1/2 : Attenuation rate of potential with light dispersed at 800 nm using a bandpass filter. V _RP : Surface potential after irradiation with white light of 50 erg / cm ² for 0.5 seconds. ΔE ^* _1/2 : variation of E1 _{/ 2} between environments measured under each environment. △ V _DDP: the charging, the amount of variation of V _DDP and early V _DDP after repeated 1000 times exposure. ΔE _1/2 indicates the amount of fluctuation in _VDDP after the charging and exposure were repeated 1000 times. ΔV _RP : V after repeating the above charging and exposure 1000 times
_RP and initial V _RP variation. The results are shown in Table 1.

Comparative Example 1 In the same manner as in Example 3 except that 1 part of X-type metal-free phthalocyanine having the X-ray diffraction spectrum shown in FIG. 5 was used.
An electrophotographic photoreceptor was prepared and electrophotographic characteristics were measured in the same manner. Table 1 shows the results.

[0029]

[Table 1]

[0030]

EFFECT OF THE INVENTION The electrophotographic photoreceptor of the present invention is prepared by using hydroxyindium phthalocyanine having a specific novel crystal form as a photoconductive material in a photosensitive layer.
It has excellent sensitivity and durability, and its use of hydroxyindium phthalocyanine extends the photosensitive wavelength range to longer wavelengths, making it very useful as a printer using a semiconductor laser. It is.

[Brief description of drawings]

FIG. 1 is a powder X-ray diffraction diagram of a hydroxyindium phthalocyanine crystal obtained in a synthesis example.

FIG. 2 is a powder X-ray diffraction diagram of amorphous hydroxyindium phthalocyanine.

FIG. 3 is a powder X-ray diffraction diagram of the hydroxyindium phthalocyanine crystal obtained in Example 1.

4 is a powder X-ray diffraction pattern of the hydroxyindium phthalocyanine crystal obtained in Example 2. FIG.

FIG. 5 is an X-ray diffraction diagram of an X-type metal-free phthalocyanine crystal.

6 is an infrared absorption spectrum of the hydroxyindium phthalocyanine crystal obtained in Example 2. FIG.

7 is a visible light / near infrared absorption spectrum of the hydroxyindium phthalocyanine crystal obtained in Example 2. FIG.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masakazu Iijima 1600 Takematsu, Minamiashigara-shi, Kanagawa Fuji Zerox Co., Ltd. Takematsu office (72) Inventor Toru Ishii 1600 Takematsu, Minamiashigara-shi, Kanagawa Fujimatsu Rocks Takematsu business In-house (56) Reference JP-A-59-155851 (JP, A)

Claims (2)

(57) [Claims] In the X-ray diffraction diagram, the Bragg angle (2θ)
± 0.2 °) of 6.9 °, 9.8 °, 14.9 °, 1
6.3 °, 19.8 °, 25.4 °, 26.6 ° and 2
A hydroxyindium phthalocyanine crystal having a strong diffraction peak at 8.1 °. 2. An electrophotographic photosensitive member comprising a conductive support and a photosensitive layer containing the hydroxyindium phthalocyanine crystal according to claim 1 provided thereon.